Apparatus for making an electrical coil



Jan.30,1934 v. G. APPLE 1,944,370

APPARATUS FOR MAKING AN ELECTRICAL COIL Filed Nov. 3, 1950- [NVENTOR A T TORNE Y throughout the several views.

Patented Jan. 30, 1934 PATENT OFFICE 1,944,870 I APPARATUS FOR m g mc AN ELECTRICAL Vincent G. Apple, Dayton, Ohio; Herbert F. Apple, Edward M. Apple, and Gourley Darroch, executors of said Vincent G. Apple, deceased Application November 3, 1930. Serial No. 492,945 4 Claims. (01. 140-4222) This invention relates to apparatus for making coils for electrical purposes and has specific reference to coils the turns of which are held together-independently of coil heads or spools such as are usuallyemployed to hold the several .tums of a completed coil together.

An object of the invention is to provide a coil in which the individual turns are surrounded by layers of insulating cement which electrically insulates the turns one from another and binds them one to another, whereby the coil is self supporting.

Another object is to provide a structure in which each turn of wire is imbedded in an infusible and insoluble body of insulation.

Another object is to provide a coil which is suflieiently hard and rigid to withstand great physical abuse, as where it may be desired to afterward press a jacket of plastic insulation around it.

Another object is to provide a coil which is extremely accurate as to shape and dimensions.

Still another object is to provide means and formulate a procedure whereby the invention .may bev practiced with a minimum expenditure in time and without loss of material.

I attainthese objects in the structure and by the means and procedure hereinafter disclosed, the disclosure being facilitated by reference to the accompanying drawing, in which- Fig. 1 is an axial section through thelwinding spool with acoilwound in place.

Fig. 2 is a detail part of the winding spool.

Fig. 3 shows-a completed coil removed from the winding spool.

Similar I numerals refer to similar parts There are now available a number of liquid insulating materials with superior insulating properties which also have the necessary cementing properties to fulfill the requirements of my invention, and which will harden by the application of heat to an infusible state, and the objects of my invention will be attained when any of these materials have been inserted and solidifled in sufficiently thick layers between the individual turns of a coil without waste of material or time, and without distortion or variation in the dimensions of the finished product.

In my cope'nding applications, Serial No. 356,586, filed April 39th, 1929, now ?atent No. 1,887,005, of -Nov. 2th, 1932, Serial No. 430,864, filed February 24th, 1930, now Patent No. 1,- 845,116 of Feb. 16th, 1932, and Serial No. 455,296, filed May 24th, 1930, now Patent No. 1,826,297 of Oct. 6th, 1931, I disclose a procedure whereby liquid insulation is deposited in a relatively thick layer around a wire while the wire is uncoiled, then dried just enough to prevent its being pressed out from between the turns when it is being woundinto coils, but not heated enough to convert it into the insoluble and infusible state until after it is wound into the coils. Steps similar to those disclosed in these copending applications may be substantially followed as part of the present process.

Fig. 1 of the drawing shows a winding spool 10 comprising a stud 11 with a large head 12, a grooved washer 13 shown in detail in Fig. 2, and a plain washer 14 held in. place by nut 15. The washer 13 has a shallow groove 16 extending through its central opening and continuing outwardly as at 17 in one side only of the washer to the outer diameter. Another shallow groove 18 extends across the edge of the washer at the periphery. A coil 19 is shown wound on the winding spool, the end 20 of the wire being at the beginning of the coil and the end 21 being at the end.

In practice wire having a cotton or other fibrous covering is treated with liquid insulation to impregnate and coat the covering. This is preferably done according to the process disclosed in the copending applications hereinbefore designated. The liquid coating is preferably dried to a stage where the coating becomes a flexible solid before it is wound onto the coil, so that the tension. incident to winding the wire will not press 13.9 coating from between adjacent turns.

When starting to wind a coil 19 the washer 13 is preferably shifted toward the washer 14 so that the end 20 of the wire may be threaded through the axial groove 16 then laid outwardly through the radial groove 1'7. The washer 13 is then pushed back against the head 12 and the winding spool is rotated until the proper number of turns have been wound, whereupon the wire is cut 011 and the end, 21 is laid in the shallow groove 18 of washer 13. The structure is now ready to be baked to bring about the final reaction of the insulation coating whereby it is first fused together into a single mass then converted into an insoluble and infusible state, and the manner in which this is carried out to prevent waste of the insulating material is an important step in the process.

The herein .zcribed process of making coils is of course applsable principally where coils are to be made in large quantities, and, for that reason a large number of winding spools 10 are preferably provided. This is particularly necesor baking consists of hestto onasingthetemperatureotthe applied heat over hours. Inthiswaythe thewireisatnotimesotpermitany torunout, ex-

!irst applying a relasidesofthecoiiandthewasherslaandu.

when reaction or the insulation is complete the may be removed from the winding spool. is preferably done by raising the lead 21 the shallow groove 18, removing the nut then holding the winding spool under the 22 o! the washer 14, and pressing on the end 23 o! the stud 11, whereby the washer 14 is periodoi'time. The proc-- the collsthen gradually in-.

its outerdiametertheneeasisliythroughthecentral opening.

2. Apparatus for making electric coils, comprising a central stud enlarged at one end to form ahead and threaded ontheiree end, a nut onthetlu'eadedportimapairoi'anallyspaced washers slightly larger than the coil on said stud between said head and nut, one resting against said head and the other against said nut, the one washer having a groove on its outer face adiacent said head extending radially from its outer to its inner diameter' then axially through its inner diameter.

3. Apparatus ior winding electric coils, com prising a central stud enlarged at one end to form a head and decreased at the free end to form a shoulder, the outer end of the decreased portion being threaded, a pair of axially spaced washers slightly larger than the coil, one on said stud against said head, the other on said decreased portion against said shoulder, and a nut on said threaded end holding said other washer against said shoulder, the one washer having a groove on its outer face adjacent said head extending radially from its outer to its inner diameter then axially through its inner diameter.

4. The apparatus defined in claim 2 but with an additional axially parallel groove in the outer diameter 01 one of the washers.

vmcnm' 6. APPLE.

III

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